Interaction of aflatoxin G1 with free DNA in vitro and possibility of its application in removing aflatoxin G1

Optimization of aflatoxin B1 removal efficiency of DNA by resonance light scattering spectroscopy

In this paper, firstly, the resonance light scattering spectra of aflatoxin B₁ (AFB₁) and DNA were measured by resonance light scattering spectroscopy (RLS), and the DNA binding saturation value (DBSV) of AFB₁ was calculated from their spectral results. Then the interaction intensity between DNA and AFB₁ and the effects of some external factors on the interaction between DNA and AFB₁ were evaluated by corresponding DBSVs, so as to establish and optimize a way for removing AFB₁ by DNA. DBSV of AFB₁ was 2.04 at 30℃ and pH 7.40. However, after adding sodium ion, calcium ion, vitamin E, vitamin C and D-glucose, DBSV of AFB₁ was changed to 2.72, 3.17, 2.67, 1.68 and 1.33 respectively. Correspondingly, the removal efficiency of AFB₁ by DNA was changed from 90.05% to 93.25%, 95.48%, 93.08%, 82.36% and 78.90% respectively. These results indicated that the external factors had a significant impact on the interaction between DNA and AFB₁. Among them, some factors enhanced the interaction between DNA and AFB₁, while some factors weakened the interaction between DNA and AFB1. The change of these external factors led to the corresponding changes in DBSV and the removal efficiency of AFB₁. DBSV of AFB₁ could really be used as an index to evaluate the intensity of the interaction between DNA and AFB₁, and to optimize the removal efficiency of AFB₁ by DNA. The experimental data also showed that the adsorption of AFB₁ to DNA was consistent with the pseudo-second-order kinetic model and the Freundlich isothermal model, was an exothermic and spontaneous process. All these results will give good references for establishing and optimizing a way of AFB₁ removal via DNA intercalation.